Axial Compressor Blade Optimization in the Low Reynolds Number Regime

Original and previously published experimental data are presented in this study of axial compressor blade optimization for use in the subcritical Reynolds number region. Three methods of increasing cascade performance at these low Rc are presented, discussed, and compared: 1) the use of sharp, leading-edge profiles, 2) trip wires or roughness elements, and 3) high freestream turbulence. The original data were collected in the VKI C-l cascade wind tunnel; during these tests, blade chord Reynolds number was varied from 250,000 down to -17,000. Each technique demonstrated an increase in low Rc performance for certain profiles, with the sharp, leading-edge profile as the potential optimum. Axial compressors or pumps that must operate for a significant amount of their design life under low Reynolds number conditions might benefit substantially from these methods.